EP0213749B1

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Info

Publication number: EP0213749B1
Application number: EP86305874A
Authority: EP
Inventors: Wilfred Joseph Samson; Jeffrey Steven Frisbie
Original assignee: Advanced Cardiovascular Systems Inc
Current assignee: Abbott Cardiovascular Systems Inc
Priority date: 1985-07-30
Filing date: 1986-07-30
Publication date: 1990-04-11
Anticipated expiration: 2006-07-30
Also published as: AU587051B2; JPH0363909B2; US4616653A; DE3670207D1; EP0213749A1; ATE51758T1; AU6055086A; JPS6272370A

Abstract

A balloon dilatation catheter (10) with an advanceable non-removable guide wire (26) having a flexible tubular member (11) with first (13) and second (17) lumens extending therethrough. An inflatable balloon (18) is carried by the distal extremity of the tubular member (11) so that the first lumen (13) extends through the balloon (18) and is out of communication with the interior of the balloon (18) and in which the second lumen (17) is in communication with the interior of the balloon (18). The guide wire (26) is slidably mounted in the first lumen (13). A coil-like tip (28) is secured to the distal portion of the guide wire (10) and has a cross-sectional area which is greater than that of the cross-sectional area of the first lumen (13) and prevents removal of the guide wire through the first lumen (13). The guide wire (26) is capable of being advanced longitudinally of the first lumen (13) so that the coil-like tip (28) of the guide wire can be advanced ahead of the balloon to facilitate the positioning of the balloon (18).

Description

This invention relates to a balloon dilatation catheter comprising a flexible tubular member, having first and second lumens extending therethrough, and an inflatable balloon which is carried by the distal portion of the tubular member, the first lumen extending through the balloon and not being in communication with the interior of the balloon, and the second lumen being in communication with the interior of the balloon.
Such a catheter is disclosed in US-A 4 411 055 (Simpson and Robert).
The size of the collapsed balloon profile in balloon dilatation catheters makes it possible to assess the potential ability of the balloon catheter to cross a lesion or stenosis. In general, the smaller the profile of the collapsed balloon, the tighter the lesion (or smaller the hole) the dilatation catheter is able to pass through.
Consequently between two dilatation catheters having the same nominal inflated balloon diameters, the one with the smaller collapsed profile conceivably can cross tighter lesions and thus has a distinct advantage over one with a larger collapsed balloon profile.
In balloon dilatation catheters using removable guide wires, such as disclosed in US-A 4 411 055, the collapsed balloon profile has been reduced by reducing the outside diameter and the inside diameter of the guide wire lumen. This permits the balloon when evacuated and folded around the lumen to have a smaller effective diameter or, in other words, a smaller collapsed balloon profile. However, there is a limitation as to how much reduction in diameter can be obtained with such an approach because it is still necessary to be able to insert and remove the guide wire with such a balloon dilatation catheter. There is therefore a need for a new and improved balloon dilatation catheter with a guide wire in which it is possible to obtain still smaller collapsed balloon profiles.
The present invention is characterised in that a guide wire is slidably disposed in and protrudes from the distal end of the first lumen, the distal end of the guide wire having a coil-like tip with a cross-sectional area which is greater than that of the first lumen and prevents removal of the guide wire through the first lumen.
In the accompanying drawings:

Figure 1 is a side elevational view of a balloon dilatation catheter, and
Figure 2 is an enlarged cross sectional view of a portion of the balloon dilatation catheter shown in Figure 1 which, in particular, shows the construction of the balloon.

As shown in the drawings, aballoon dilatation catheter 10 comprises a flexible elongate tubular member 11 having a first elongate flexibletubular element 12 which is provided with afirst lumen 13 extending therethrough. The distal portion of thetubular element 12 is provided with a portion 12a of reduced diameter with atapered transition portion 12b which adjoins a portion 12c of a larger diameter extending to the proximal extremity of the first tubular element.
A second elongate flexibletubular element 16 is also provided which extends over the first elongatetubular element 12 and is disposed coaxially therewith. The second elongatetubular element 16 is of a size so that there is provided between the first and secondtubular elements 12 and 16 an annular lumen 17 extending the length of thetubular elements 12 and 16. Aballoon 18 is carried by the distal portion of thetubular element 16 near the distal extremity thereof and has its interior in communication with the lumen 17. Theballoon 18 is formed integral with the secondtubular element 16.
The first and secondtubular elements 12 and 16 can be formed of a suitable flexible thermo-plastic material such as a polyolefin or polyvinylchloride.
The distal extremity of the second elongatetubular element 16 is shrunk onto the distal extremity of the firsttubular element 12 to form a liquid-tight seal between their distal ends. The lumen 17 opens into theballoon 18 and can be used for inflating and deflating the balloon. If desired, instead of forming theballoon 18 integral with the second elongatetubular element 16, it can be formed as a separate element and bonded to the secondtubular element 16 by suitable means such as an adhesive.
Anadapter 21 is secured to the proximal extremity of the tubular member 11. Theadapter 21 is of a conventional type and is provided with a main orcentral arm 22 and aside arm 23. Themain arm 22 is in communication with thelumen 13 of the firsttubular element 12 and is adapted to carry aguide wire 26. Theguide wire 26 can be formed by a suitable material such as stainless steel and is provided with an elongate portion 26a, a necked down taperedportion 26b and aportion 26c at the distal extremity which is of substantially reduced diameter. A spring-like coil 28 is secured to the distal extremity of theguide wire 26 and is in the form of a helix. The proximal end of thecoil 28 is secured to the distal portion of theguide wire 26 bysolder 29. Asemi-spherical tip 31 is provided at the distal extremity of thecoil 28 and joins the tip of thewire 26 to the coil. Thecoil 28 is formed of a suitable material, for example platinum. Thetip 31 is formed of a suitable material such as gold.
Aband 36, which serves as a marker, is provided on the portion 12a of the firsttubular element 12 and is disposed substantially equidistant between the extremities of theballoon 18.
Atorquer 41 of a conventional type is secured to the proximal extremity of theguide wire 26 and is adapted to be grasped by hand for rotating the guide wire as hereinafter described.
If it is assumed that theballoon 18 has a diameter of 2 mm when fully inflated, the balloon dilatation catheter shown in Figures 1 and 2 of the drawings can have dimensions such as the following: The tubular member 11 extending from theadapter 21 to theballoon 18 can have a suitable length ranging from 40 to 50 cm and preferably a dimension of approximately 135 cm. The portion 12c of the first or innertubular element 12 can have an outside diameter ranging from 0.064 to 0.86 mm (0.025 to 0.034 inch), an inside diameter of 0.36 to 0.51 mm (0.014 to 0.020 inch) and preferably 0.69 and 0.41 mm (0.027 and 0.016 inch) respectively. The portion 12a can have an outside diameter of 0.41 to 0.56 mm (0.016 to 0.022 inch) and an inside diameter of 0.2 to 0.3 mm (0.008 to 0.012 inch) and preferably dimensions of 0.51 mm (0.020 inch) for the outside diameter and 0.25 mm (0.010 inch) for the inside diameter. The secondtubular element 16 can have an outside diameter of 0.97 to 1.21 mm (0.038 to 0.048 inch) and an inside diameter of 0.84 to 1.07 mm (0.033 to 0.042 inch) and preferably an outside diameter of 1.14 mm (0.045 inch) and an inside diameter 0.97 mm (0.038 inch). Theballoon 18, 2 mm in size can have a collapsed profile of 0.76 to 0.97 mm (0.030 to 0.038 inch) and can have a suitable length of, for example, 15 to 35 mm and preferably a length of approximately 25 mm. The distal extremity of thecatheter 10 in which the distal extremities of the first and secondtubular elements 12 and 16 are bonded together can have a suitable dimension ranging from 0.61 to 0.76 mm (0.024 to 0.030 inch) and preferably a dimension of 0.66 mm (0.026 inch). This extremity can have a length ranging from 3 to 10 mm and preferably a length of approximately 5 mm. The portion 26a of theguide wire 26 can have a dimension ranging from 0.33 to 0.36 mm (0.013 to 0.014 inch) and if desired can be coated with a suitable material such as PTFE. Theportion 26c of theguide wire 26 can have a dimension such as 0.18 to 0.2 mm (0.007 to 0.008 inch). Thecoil 28 can have an outside diameter of 0.3 to 0.41 mm (0.012 to 0.016 inch) and preferably of approximately 0.38 mm (0.015 inch). Thecoil 28 can have a length ranging from 15 mm to 50 mm and preferably has a length of approximately 30 mm. Theradiopaque marker band 36 can have an internal diameter of 0.53 mm (0.021 inch) with a wall thickness of 0.05 mm (0.002 inch) and a width of approximately 1.14 mm (0.045 inch).
Operation and use of the balloon dilatation catheter as shown in Figures 1 and 2 is now briefly described as follows. Assume that a stenosis is to be crossed. Thecatheter 10 with theballoon 18 in a collapsed state is introduced into the vessel in a conventional manner. Theguide wire 26 can be utilized to facilitate the introduction and advancement of thedilatation catheter 10. Its progress can be observed upon a fluoroscope because thecoil 28 is relatively opaque to X-rays. Although theguide wire 26 cannot be retracted from the catheter, it is independently manipulable with respect to the balloon dilatation catheter. For example, if desired the distal extremity of theguide wire 26 and, in particular, thecoil 28 can be advanced so it is 7.6 to 10 cm (3 to 4 inches) ahead of the catheter. It also can be rotated by use of thetorquer 41.
By utilizing such aguide wire 26 with the dilatation catheter herein described, it is possible to reduce the profile of the dilatation catheter substantially with the only disadvantage being that the guide wire cannot be removed. The amount of travel of theguide wire 26 is determined by the length of theportion 26c of the guide wire. When thetapered portion 26b enters thetapered portion 12b of the firsttubular element 12, further travel is inhibited. The rearmost extremity of theguide wire 26 is determined when thesolder 29 reaches the distal extremity of the first flexibletubular element 12. Typically this ex- tendability or advanceability of the guide wire in the dilatation catheter can vary from 10 to 20 cm. The amount of advancement of theguide wire 26 can also be adjusted within the limits just described by the positioning of thetorquer 41 on the guide wire.
After the dilatation catheter has been positioned in the stenosis, theballoon 18 can be inflated by introducing a radiopaque contract liquid through theside arm 23. Themarker 36 provided within theballoon 18 facilitates the positioning of the balloon in the stenosis prior to inflation. After theballoon 18 has been inflated one or more times, the balloon can be deflated and the balloon removed from the stenosis and thedilatation catheter 10 removed from the vessel.

Claims

1. A balloon dilatation catheter (10) comprising a flexible tubular member (11), having first and second lumens (13, 17) extending therethrough, and an inflatable balloon (18) which is carried by the distal portion of the tubular member (11), the first lumen (13) extending through the balloon (18) and not being in communication with the interior of the balloon, and the second lumen (17) being in communication with the interior of the balloon (18), characterised in that a guide wire (26) is slidably disposed in and protrudes from the distal end of the first lumen (13), the distal end of the guide wire (26) having a coil-like tip (28) with a cross-sectional area which is greater than that of the first lumen (13) and prevents removal of the guide wire (26) through the first lumen (13).

2. A catheter as claimed in claim 1, characterised in that means (41) is secured to the proximal end of the guide wire (26) to facilitate rotation of the guide wire in the first lumen (13).

3. A catheter as claimed in claim 1 or 2, characterised in that the flexible tubular member (11) comprises a first tubular element (12) through which extends the first lumen (13) and a second tubular element (16) which extends co-axially over the first element (12), the first and second tubular elements forming the second lumen (17), the inflatable balloon (18) being carried by the second tubular element (16).